The invention relates to laminated polarizers which comprise a polarizing core layer made from a polymer containing polyacetylene (PAC) and adhesive layers on one or both sides made from a particular polyurethane-polyurea, each of the said adhesive layers being able to accept a transparent outer layer.
The production of laminates made from different substrates with adhesive (sticking) layers located between them is known. BE No. 617,286 discloses a laminate made from an optical element and glass using a cross-linked epoxy resin as adhesive layer. In order to cross-link the said epoxy resin, it has to be reacted at 95.degree. C. for 48 hours. Examples of other known adhesive layers are: epoxy resins which cure with amines, acid anhydrides or polyamides (DE-OS No. 1,594,044; U.S. Pat. No. 4,416,946); acrylate systems, which may be monomeric or oligomeric systems with vinyl groups, which can be cured by thermal, free radical or photochemical means after application of the outer layer [JP Nos. 56/33,610 (1981), 59/58,410 (1984), 59/48,714 (1984), 58/171,008 (1983)]; mixtures of polyacrylates with phenolic resins, which are applied in solution [JP No. 55/155,307 (1980)]; isocyanate adhesives [JP No. 53/47,696 (1978)] and polyurethanes [JP No. 60/159,704 (1985)].
While with many laminates, mechanical properties such as strength, energy absorption characteristics (safety glasses) and an adequate adhesion of the laminate components generally are of paramount importance, there are other additional requirements in the case of the highly effective laminated polarizers according to the invention; namely:
(1) high transparency, all clouding phenomena having to be excluded, PA0 (2) a high degree of light fastness PA0 (3) protection of the polarizing core layer from chemical environmental influences PA0 (4) compatibility of the adhesive layers and if appropriate of the outer layers with the polarizing core layer without impairment of the optical properties.
In principle, it is also possible to use the adhesive layers mentioned above for the lamination of polymers containing polyacetylene, whose matrix is a polymer with polar groups. The polyurethane-polyureas described in more detail below are, however, advantageously suitable for this purpose.
Laminated polarizers have been found made from a polarizing core layer and adhesive layers on one or both sides, each of which can accept a transparent outer layer, the polarizer being a polymer product containing polyacetylene the matrix of the polymer product being a polymer having polar groups.